Abstract: The transformation of the sheet into products without failure and excess of material in a sheet metal forming operation means that the blanks should be correctly designed. Due to the earing or non-uniform flange in sheet metal forming, caused by non-uniform material flow and planar anisotropy in the sheet, shape differences exist between the forming parts and target parts. In order to obtain a reasonable blank, the node mesh mapping method is proposed. Combining with the inverse finite element analysis and incremental analysis, the blank shape is optimized according to the mapping relationship and the flow tendency of material points. To test the proposed method, blank shape optimizations in the forming processes of a square box part and an electric car B-pillar are presented respectively. The results show that for more complex industrial parts, the method proposed in this paper can obtain a reasonable blank shape after a finite optimization, and the required shape of the target part is consistent with the shape after forming with a reasonable blank.

Key words: inverse finite element method; blank design; node mesh mapping method; sheet metal forming